Synsepalum dulcificum is a plant known for its berry that, when eaten, causes sour foods (such as lemons and limes) subsequently consumed to taste sweet. This effect is due to miraculin. Common names for this species and its berry include miracle fruit,[2]miracle berry, miraculous berry,[2]sweet berry,[3][4][5] and in West Africa, where the species originates, agbayun,[6]taami, asaa, and ledidi.

The berry itself has a low sugar content[7] and a mildly sweet tang. It contains a glycoprotein molecule, with some trailing carbohydrate chains, called miraculin.[8][9] When the fleshy part of the fruit is eaten, this molecule binds to the tongue's taste buds, causing sour foods to taste sweet. At neutral pH, miraculin binds and blocks the receptors, but at low pH (resulting from ingestion of sour foods) miraculin binds proteins and becomes able to activate the sweet receptors, resulting in the perception of sweet taste.[10] This effect lasts until the protein is washed away by saliva (up to about 30 minutes).[11]

The berry has been used in West Africa since at least the 18th century, when European explorer the Chevalier des Marchais[12] provided an account of its use there. Marchais, who was searching West Africa for many different fruits in a 1725 excursion, noticed that local people picked the berry from shrubs and chewed it before meals. In the 1970s in the USA, an attempt was made to commercialize the fruit for its ability to turn unsweet foods into sweet foods without a caloric penalty, but ended in failure when the U.S. Food and Drug Administration (FDA) classified the berry as a food additive.[7] There were controversial circumstances with accusations that the project was sabotaged and the research files stolen by the sugar industry to prevent loss of business caused by a drop in demand for sugar.[13] However, the FDA has denied receiving any pressure from the sugar industry.[14] Arguments similar to the ones used for this classification were used for the FDA's regulation on stevia now labeled as a "dietary supplement" instead of a "sweetener".

For a time in the 1970s, USdieters could purchase a pill form of miraculin.[15] This phenomenon has enjoyed some revival in food-tasting events, referred to as "flavor-tripping parties" by some.[16] The tasters consume sour and bitter foods, such as lemons, radishes, pickles, hot sauce, and beer, to experience the taste changes.

It is a shrub that grows between 1.8 and 4.5 meters (6 to 15 feet) in height and has dense foliage.[17][18] Its leaves are 5–10 cm long, 2-3.7 cm wide and glabrous below. They are clustered at the ends of the branchlets. The flowers are white. It carries red, 2 cm long fruits. Each fruit contains one seed.[4]

The plant grows best in soils with a pH as low as 4.5 to 5.8, in an environment free from frost and in partial shade with high humidity. It is tolerant of drought, full sunshine and slopes.[4]

The seeds need 14 to 21 days to germinate. A spacing of 4 m between plants is suggested.[4]

The plants first bear fruit after growing for approximately 3–4 years,[4] and produce two crops per year, after the end of the rainy season. This evergreen plant produces small, red berries, while white flowers are produced for many months of the year.

The berry is on the EU list of Novel Foods, and requires a safety assessment before it can be sold as food or used as a food additive.[23]

In Japan, miracle fruit is popular among patients with diabetes and dieters.[8][9]

The shelf life of the fresh fruit is only 2–3 days.[citation needed] Because miraculin is denatured by heating, the pulp must be preserved without heating for commercial use.[citation needed] Freeze-dried pulp is available in granules or in tablets, and has a shelf life of 10 to 18 months.[citation needed]

^ abMcCurry, Justin (2005-11-25). "Miracle berry lets Japanese dieters get sweet from sour". London: The Guardian. Retrieved 2008-05-28. The berries contain miraculin, a rogue glycoprotein that tricks the tongue's taste-bud receptors into believing a sour food is actually sweet. People in parts of west Africa have been using the berries to sweeten sour food and drink for centuries, but it is only recently that the global food industry has cottoned on.

^ abcdSlater, Joanna (2007-03-30). "To Make Lemons Into Lemonade, Try 'Miracle Fruit'". Wall Street Journal. Retrieved 2008-05-28. Two American entrepreneurs, Robert Harvey and Don Emery, tried this route back in the 1970s, but the venture failed.[specify] They initially focused products for diabetics, but some of their financial backers, who included Reynolds Metals Company and Barclays Bank PLC, had a loftier goal.

^"The miracle berry". BBC. 2008-04-28. Retrieved 2008-05-28. I honestly believe that we were done in by some industrial interest that did not want to see us survive because we were a threat. Somebody influenced somebody in the FDA to cause the regulatory action that was taken against us.